The only way to get molasses in bulk is to buy it from someone else who buys it by the tank car load. You have to bring in your own jugs or barrels.

Look for a farmer's co-op. You might have to join it to get the bulk price. Current bulk prices around here are $0.09-$0.11 per pound. A gallon weighs 10.5 pounds, so 55 gallons would cost a little over $50.

Molasses is a microbial stimulant - a food. Normally soil microbes get their sugars from plant roots which trade the plant's excess sugar for the microbe's excess nutrients. The microbes in nature get their protein from dead animals and plants lying on the ground. Organic fertilizers usually provide protein in the form of ground up grains, nuts, and beans. Some of the popular ones include corn meal, alfalfa meal, coffee beans, soy, canola, etc. But the microbes still need sugar, energy, to reproduce and all that other microbial stuff.

A common use for molasses is to spray on plants to stimulate the microbial populations living on the outside leaves, stems, flowers, and trunks of the plants. The stimulation of the microbes often stimulates the plant's immune system so that the plants essentially become protected from disease and from insects. Another benefit seems to be an increased production of natural sugar to the roots which benefits the soil microbes. A good application rate is 1 gallon of molasses per acre or 3 ounces per 1,000 square feet. You can dilute with as much water as makes you happy as long as you get all 3 ounces on 1000 square feet.